810 FISHES. 



c. Pharyngeal bones very broad and strong ; tlie lower 

 7 to 10 teeth on each side, greatly enlarged and trun- 

 cate ; the teeth on the upper part of the bone small, 

 aa usual in the family. . . Placophabynx, 3. 



ce. Pharyngeal bones not especially enlarged; the teeth 

 strongly compressed, of the usual type. 



Mtxostoma, 3. 

 66. Air bladder in two parts. 



d. No lateral line Ekimyzon, 5. 



dd. Lateral line imperfect. . . Minttrbma, 4. 

 ddd. Lateral line well developed ; lips tuberculate, 

 e. Fontanelle distinct; no mandibulary sheath. 

 /. Scales moderate, not crowded forwards, about 

 equal over the body ; body long and little com- 

 pressed; head transversely concave between 

 orbits, long and flattened; the physiognomy 

 being therefore peculiar; ventral rays 9. 



Hypbntblidm, 6. 

 ff. Scales small, smaller anteriorly and much 

 crowded; head transversely convex between 

 orbits ; ventral rays normally 10. 



Catostomtjs, 7. 

 * Body much elongated, sub-cylindrical forwards ; dorsal elongate, 

 falciform, of 30 or more rays ; fontanelle obliterated by the 

 union of the parietal bones. {Oycleptina.) 



g. Mouth small, subinferior, with papillose lips ; scales rather 



small Ctcleptus, 8. 



*** Body oblong oval, compressed; dorsal elongate, elevated in 

 front, of 20 or more rays; fontanelle present. (Buba- 

 Uchfhyinm.) 

 h. Dorsal rays about 30 in number (34 to 38) ; anal rays about 

 10 (9 to 12) ; scales large. 

 i. Pharyngeal bones narrow, with the teeth relatively thin and 

 weak. 

 j. Mouth small, inferior, protractile downwards ; dorsal fin 

 often greatly elevated. , . , Caepiodeb, 9. 



